Gas-fired apparatus, such as residential gas-fired water heaters, often include a main gas burner to provide heat for the apparatus, and a pilot burner that provides a standing pilot flame to ignite the main gas burner (e.g., for the first time or if the main burner flame goes out). In the case of water heaters, a main gas burner is used to heat water within a water tank of the water heater. A thermostat is typically provided to control the temperature of the water inside the tank and typically may be set within a particular range (e.g., warm, hot or very hot). A pilot burner provides a standing pilot flame to ignite the main gas burner. To ignite the pilot flame in typical gas-fired apparatus, a user holds a pilot valve open (e.g., with a depressible knob) to permit gas to flow to the pilot burner, and ignites the gas at the pilot burner with an ignition source, such as an electronic igniter or a match.
At least some known gas flow controllers include flow regulators (e.g., servo-regulated valves) to regulate a flow of gas to the pilot burner and/or the main burner. Operation of such flow regulators may be impaired if the components of the flow regulators are exposed to pressures exceeding defined operating pressures, or “over-pressure conditions”. In some instances, exposure to over-pressure conditions may damage components of the flow regulators, requiring repair or replacement.
At least some known gas flow controllers do not provide sufficient protection of components (e.g., servo-regulated valves) from over-pressure conditions. For example, some gas flow controllers permit gas flow along flow paths including flow regulators under abnormal operating conditions, such as an elevated or over-pressure condition at the inlet or upstream side of the pilot valve. This may result in excessive gas flow to the pilot burner, and may expose components of the gas flow controller to excessive pressures, impairing operation and/or damaging such components.
This Background section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.